The aim of this study was to identify the efficacy and safety of Baweidihuang-wan (BWDH) in women with overactive bladder (OAB) and to investigate whether BWDH is more effective in OAB diagnosed as kidney yang deficiency pattern by the Korean medical pattern identification. The design of this study was a randomized, double blind, placebo controlled trial. One hundred eighty-six women with OAB were randomized to treatment (n=93) or control group (n=93). Participants received BWDH or placebo three times a day for eight weeks. Efficacy was assessed by overactive bladder symptom score and 3-day bladder diary. Subgroup analysis was conducted between kidney yang deficiency pattern and other patterns according to the Korean medical pattern identification. One hundred sixty-four participants completed this trial. The treatment group has improved in OABSS score, Total micturitions per 24 hr, Daytime micturitions per 24 hr, Total count of urgency, and Total urgency score over the control group, but differences were not statistically significant. By a subgroup analysis, OABSS score, total micturitions per 24 hr, total count of urgency and total urgency score improved most in the treatment group with the kidney yang deficiency pattern but this was also not statistically significant. No obvious adverse events were found in the use of BWDH. In conclusion, this trial did not show significant difference between BWDH and placebo in women with OAB. However BWDH tended to improve urinary frequency and urgency in OAB, especially diagnosed as kidney yang deficiency pattern. Further additional research will be needed.